const base64Str = 'emhhbmdzYW46MTIzNDU2';

// 将base64字符串转换回Buffer
const decodedBuffer = Buffer.from(base64Str, 'base64');

// 转换为UTF-8字符串
const decodedStr = decodedBuffer.toString('utf8');

console.log('用户名：' + decodedStr.split(':')[0]);
console.log('密码：' + decodedStr.split(':')[1]);